1. Field of the Invention
The invention relates to portable refuse containers and means for dumping the contents of such containers. In particular, the invention relates to dumping mechanisms adapted to be mounted on a garbage truck and useful for inverting the refuse container and dumping its contents into the truck receptacle.
2. Description of the Prior Art
The prior art discloses a number of systems for automatically emptying household size refuse containers into larger refuse vessels, such as garbage trucks.
The closest known system is described in U.S. Pat. No. 3,738,516. This patent system includes a "low profile," portable plastic refuse container having a metal frame outer structure which forms two handles and a base support and mounts a pair of wheels. The metal frame also forms a pair of vertically spaced locking bars on a front surface of the container. The garbage truck is provided with a vertically swingable frame at the base of an opening in the truck wall. The frame has a pair of non-moving hooks which receive the container locking bars for lifting the container and dumping its contents. When the frame is in its normally lowered retracted position, only the upper hook and locking bar are engaged. Midway through the rotation and inversion, the container slides down a small distance so that the other hook and locking bar engage. Thus, only one hook is supporting the container at any given time. This system has the principal disadvantage of not positively locking the container to the frame during the dumping operation.
Two variations of another prior art system are described in U.S. Pat. Nos. 3,804,277 and 3,894,642. This system is manufactured by Rubbermaid Industrial Products Corporation of Statesville, N.C. Both variations of this system incorporate a portable waste container having on one side a lower cross bar and an upper downwardly opening recess. The truck-mounted dumping mechanism has an upper saddle which engages the recess and a lower downwardly directed, pivotal hook for engaging the cross bar. In one variation, the frame mounts a cam-operated linkage and in the other variation a lift arm which pivots the lower hook over and behind the lower cross bar in response to the rotation of the frame to invert the receptacle.
Other similar systems are the "Roll-A-Waste" system manufactured by the Molded Plastics Products Division of United States Steel, Pittsburgh, Pa., and the "Peli-Can" system manufactured by P. P. I. Industries, Inc., of Elk Grove Village, Ill. A summary of all four of the above systems may be found in the September/October 1975 "Refuse Report" published by the International City Management Association.